Use this oenology calculation to document or plan a defined fermentation, blending, adjustment, stabilization, aging, packaging, sensory, or cellar operation from measured wine parameters.

Critical temperature (°C)

Critical temperature selected for the yeast and must conditions.

Exposure (h)

Hours the must spends at the elevated temperature.

Must temperature (°C)

Measured fermentation temperature.

Calculate temperature-exposure degree-hours above a caller-selected critical temperature; the index quantifies exposure but does not independently predict yeast injury. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Heat stress index

Degree-hours of heat stress above the critical point.

Temperature excess (°C)

Degrees above the critical temperature.

• Wine chemistry and microbiology depend on temperature, pH, alcohol, sugar, matrix, measurement method, microbial state, legal limits, product formulation, and bench-trial response. Generic doses and thresholds are not production instructions for every wine.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Confirm measurements with calibrated winery methods, run scaled bench trials, record additions and lot volumes, check local regulations and supplier specifications, and obtain professional laboratory advice for faults or stability risks.

• Fructose-Glucose Ratio Checker

  Calculate the fructose-to-glucose ratio and compare it with caller-selected watch and fructose-dominant thresholds; the ratio alone does not diagnose a stuck fermentation.

• Native Fermentation Risk Score Calculator

  Apply a caller-defined linear scoring model to free SO2 above a baseline and temperature below a baseline; this configurable heuristic is not a microbiological prediction.

• Red Wine Polymeric Pigment Index Checker

  Compare a polymeric-pigment assay result with a caller-selected threshold; crossing the threshold does not by itself establish long-term color stability.